The Year in Biomedicine

The Year in Biomedicine

A new approach to brain surgery, tested by a Swiss team earlier this year, allows surgeons to burn out small chunks of brain tissue without major surgery using specialized sound waves (“Brain Surgery Using Sound Waves”). Neurosurgeons used a technology developed by InSightec, an ultrasound technology company headquartered in Israel. The method employs high-intensity focused ultrasound (HIFU) to target the brain. (HIFU is different than the ultrasound used for diagnostic purposes, such as prenatal screening, and has previously been used to remove uterine fibroids.) Beams from an array of more than 1,000 ultrasound transducers are focused through the skull onto a small piece of diseased tissue, heating it up and destroying it. In the study, nine patients with chronic debilitating pain reported immediate pain relief after the procedure.

Scientists also hope to co-opt the technologies developed for HIFU to modulate brain activity, using low intensity focused ultrasound to activate nerve cells (“Targeting the Brain with Sound Waves”). This approach might one day provide a less invasive alternative to deep-brain stimulation. This procedure, in which surgically implanted electrodes stimulate parts of the brain, is an increasingly common treatment for Parkinson’s disease and other neurological problems.

In another first for the brain, scientists discovered this year that our IQ, or general intelligence, depends in large part on our white matter–the fatty layer of insulation that coats the neural wiring of the brain (“Brain Images Reveal the Secret to Higher IQ”). Using a type of brain imaging called diffusion tensor imaging, researchers analyzed the neural wiring in 92 pairs of fraternal and identical twins and found a strong correlation between the integrity of the white matter and performance on a standard IQ test. In addition, the researchers found that the quality of one’s white matter is largely genetically determined. They are now searching for genetic variants tied to white matter and IQ.

A feature in the November issue of the magazine further explored the secret of intelligence, revealing that our smarts may be determined by the function and efficiency of the networks within the brain, rather than the number of neurons or the size of any particular region (“Intelligence Explained”).